Hello, I recently discovered a lump on my inner left thigh. Just below my groin area.

The lump just seem to have sprang up over night as I didn't feel anything before then.
The lump is about 1" maybe a little less...
The lump itself is fairly hard..
Also I'm 18 just turned last September...
But it is also pretty painful, as I'm fairly overweight my thigh's often rub, and this causes it to output a bit of pain, also when I touch it it hurt's.
Recently I have been doing work with my dad at weekend's outside, and last weekend it was throwing it down with rain and I was in mud all day. Shortly afterwards I found this lump. Could it be a Cyst, infection or something worse?
I am planning on going to the local GP.
Also I had a salt bath before.. Just to see if it is an infection if it is and I continue salt baths it should subside within a few day's...

At your age it's not likely to be cancer, but it should be checked out. However, given the activity you've been doing lately, I'd more likely suspect that it might be a boil. That should be seen by a doctor, as they can lance it safely and let it drain, and tell you how to prevent further infection, but it's not a big deal if that's what it is.

Well when I woke up this morning it wasn't emitting as much pain, and it is still there however it has decreased in size. It still has the hard edges and is still perfectly "round".
So this made me feel better, and also thank you so much for replying I really do feel much better now I will see my GP on Monday.